The present disclosure relates to apparatus and methods for the control of electric motors, and more particularly for methods and apparatus for the control of permanent magnet motors, still more particularly to field weakening strategies for permanent magnet AC motors.
Permanent magnet motors offer a number of advantages, and their use in various applications is increasing. In the control of permanent magnet motors field weakening phenomena may be exploited to control motor performance. In particular, field weakening schemes enable the operating limits of permanent magnet motors to be expanded by modifying the current vector control in view of the modulation index.